The present invention relates generally to apparatus and methods for closing and/or sealing openings into body lumens, and more particularly to apparatus and methods for delivering a vascular closure element for closing a puncture in a blood vessel formed during a diagnostic or therapeutic procedure.
Catheterization and interventional procedures, such as angioplasty or stenting, generally are performed by inserting a hollow needle through a patient""s skin and muscle tissue into the vascular system. A guide wire may then be passed through the needle lumen into the patient""s blood vessel accessed by the needle. The needle may be removed, and an introducer sheath may be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to a dilator. A catheter or other device may then be advanced through a lumen of the introducer sheath and over the guide wire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate introduction of various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure.
Upon completion of the procedure, the devices and introducer sheath may be removed, leaving a puncture site in the vessel wall. External pressure may be applied to the puncture site until clotting and wound sealing occur. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a physician""s or nurse""s time. It is also uncomfortable for the patient, and requires that the patient remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.
Various apparatus have been suggested for percutaneously sealing a vascular puncture by occluding the puncture site. For example, U.S. Pat. Nos. 5,192,302 and 5,222,974, issued to Kensey et al., describe the use of a biodegradable plug that may be delivered through an introducer sheath into a puncture site. When deployed, the plug may seal the vessel and provide hemostasis. Such devices, however, may be difficult to position properly with respect to the vessel, which may be particularly significant since it is generally undesirable to expose the plug material, e.g., collagen, within the bloodstream, where it may float downstream and risk causing an embolism.
Another technique has been suggested that involves percutaneously suturing the puncture site, such as that disclosed in U.S. Pat. No. 5,304,184, issued to Hathaway et al. Percutaneous suturing devices, however, may require significant skill by the user, and may be mechanically complex and expensive to manufacture.
To facilitate positioning devices that are percutaneously inserted into a blood vessel, xe2x80x9cbleed backxe2x80x9d indicators have been suggested. For example, U.S. Pat. No. 4,317,445, issued to Robinson, discloses a flashback chamber on a first end of a cannula that communicates with a port on a second end. The second end is percutaneously introduced into a patient until the port enters the vessel, whereupon blood, under normal blood pressure, may advance along the cannula and enter the flashback chamber, thereby providing a visual indication that the vessel has been entered. This reference, however, does not discuss vascular wound closure, but is merely directed to an introducer device. In contrast, U.S. Pat. No. 5,676,974, issued to Kensey et al., discloses a bleed back lumen intended to facilitate positioning of a biodegradable plug within a puncture site. This device, however, requires that an anchor of the plug be positioned within the vessel, and therefore, may increase the risk of over-advancement of the plug itself into the vessel.
Alternatively, U.S. Pat. No. 5,674,231, issued to Green et al., discloses a deployable loop that may be advanced through a sheath into a vessel. The loop is intended to resiliently expand to engage the inner wall of the vessel, thereby facilitating holding the sheath in a desired location with respect to the vessel. The loop may also provide a support for facilitating the deployment and deflection of a surgical clip against the vessel wall. Such a device, however, may risk engagement between the loop and the surgical clip, thereby preventing the loop from being withdrawn from the vessel.
Accordingly, apparatus and methods for delivering a device for closing a vascular puncture site would be considered useful.
The present invention is directed to apparatus and methods for closing and/or sealing openings into body lumens, and more particularly to apparatus and methods for delivering a vascular closure element for closing a puncture in a blood vessel formed during a diagnostic or therapeutic procedure.
In accordance with one aspect of the present invention, an apparatus is provided for delivering a closure element into engagement with tissue adjacent an opening into a body lumen. The apparatus includes a sheath including a lumen extending between its proximal and distal ends, and a locator member disposed within the sheath, the locator member having a distal portion extending distally beyond the distal end of the sheath. One or more positioning elements are provided on the distal portion of the locator member, the positioning elements being selectively expandable between a substantially axial collapsed configuration and a substantially transverse expanded configuration. Preferably, the positioning elements are a plurality, e.g. two or more, equally spaced, substantially flexible splines or wings configured for expanding substantially transversely to a longitudinal axis of the sheath. Each spline may have a first fixed end and a second movable end, the second end being axially movable towards the first end to cause an intermediate region of the spline to expand radially outward, thereby defining the radially expanded configuration. Alternatively, the splines may include a plurality of substantially rigid or semi-rigid elements that are hinged such that the splines may be expanded to the expanded configuration.
An actuator may be coupled to the locator member, the actuator configured for controllably expanding the positioning elements from the collapsed configuration to the expanded configuration. The actuator may include a control such that the positioning elements may be selectively expanded to one of a plurality of expanded sizes, e.g., to accommodate insertion into vessels of various sizes.
A housing may be axially slidably disposed on an exterior of the sheath, the housing configured for releasably holding a closure element, the housing being actuable for advancing the closure element distally to deploy the closure element. In a preferred embodiment, the locator actuator may be configured for automatically collapsing the positioning elements to the collapsed configuration upon advancement of the housing to prevent engagement between the closure element and the positioning elements. The housing may be substantially permanently but slidably disposed on the sheath. Alternatively, the housing may be provided separate from the sheath, e.g., with the closure element pre-loaded therein. The housing may be directed over the sheath, e.g., over the proximal end of the sheath, at any time before delivery of the closure element.
In accordance with another aspect of the present invention, a method is provided for delivering a closure element into a passage communicating with an opening in a wall of a body lumen. An introducer sheath is positioned through a patient""s skin towards the body lumen via the passage, the sheath including a lumen extending between its proximal and distal ends. One or instruments may be introduced through the lumen of the sheath into the body lumen. A diagnostic or therapeutic procedure may be performed using the one or more instruments at a location accessed via the body lumen.
In a preferred embodiment, the body lumen is a blood vessel, such as a peripheral vessel, e.g., the femoral or carotid artery. The procedure may be any of a variety of endovascular procedures, such as angioplasty, atherectomy, stent delivery, delivery of a therapeutic agent, and tissue ablation.
Upon completion of the procedure, the devices may be removed from the sheath. A locator may be inserted along or through the sheath until a distal portion of the locator extends beyond the distal end of the sheath and into the body lumen. One or more positioning elements on the distal portion of the locator may be expanded from a collapsed configuration to an expanded configuration.
The sheath and locator may then be manipulated with respect to the body lumen until the positioning elements in their expanded configuration contact the wall of the body lumen, thereby providing a tactile indication of a location of the distal end of the sheath. A closure element may then be delivered via the sheath into the passage. The sheath and locator may be withdrawn from the body lumen and opening, leaving the closure element to substantially close the opening.
In a preferred embodiment, the closure device is delivered via a housing slidably attached to the sheath. The housing may be advanced distally, e.g., along an exterior of the sheath, the housing having the closure device detachably held thereto. In a preferred method, the positioning elements may automatically return to the collapsed configuration when the housing is advanced to its distal position, thereby avoiding engagement between the closure element and the positioning elements. Alternatively, the positioning elements may automatically collapse when an ejector is activated to deploy the closure element from the housing, e.g., after the housing has been advanced to its distal position.
Other objects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.